With Congress deadlocked over fiscal policy and a government shutdown looming, personal disputes have clouded the usually collegial Senate, straining relationships between lawmakers who otherwise work well together.

Compared with the raucous House of Representatives, the Senate historically has been an island of calm and deliberation. George Washington is said to have described it to Thomas Jefferson as the saucer to cool the hot tea of the House.

But with Republican efforts to defund President Barack Obama’s signature accomplishment – the overhaul of health care – and threats to shutter much of the government or cause the country to default on its debt, some of the House’s heat has spilled over into the Senate. And some worry that it’s poisoned the atmosphere.

“Overall, the environment is much more contentious and hostile,” said former Sen. Olympia Snowe, a Maine Republican who left the Senate last January, partly in frustration over increasing partisanship. “Hopefully, it will blow over. Otherwise, it comes at the detriment of the country.”

In the space of a week, Sen. David Vitter, a Louisiana Republican, filed two ethics complaints against Sen. Barbara Boxer of California and Senate Majority Leader Harry Reid of Nevada, both Democrats.

Democrats had blocked Vitter from getting a vote on an anti-Obamacare amendment. So Vitter blocked passage of an energy bill. Then, news reports surfaced that Democrats were trying to get back at Vitter by, among other things, bringing up his involvement in a 2007 prostitution scandal.

Vitter perceived that Boxer and Reid were behind the effort. He told the news outlet Politico that Reid was acting like “an old-time Las Vegas mafia thug.”

The Senate Select Committee on Ethics rejected Vitter’s first complaint Tuesday. On Thursday, he filed another.

“Well, I have news for them,” Vitter said in a statement. “I’m not going away and this issue isn’t going away.”

Boxer, who leads the ethics panel but declined to get involved in the Vitter complaint, called his allegations “baseless.”

“This whole matter has gone from bizarre to surreal,” she said in a statement. “I believe a senator using the Ethics Committee to launch political attacks is unprecedented and outrageous.”

Personal frustration is revealing itself on the Senate floor, too.

When Sen. Ted Cruz, a freshman Texas Republican, spoke for more than 21 hours against the health care law this week, he chastised his Republican colleagues for giving up on efforts to defund it, comparing that to Britain’s appeasement of the Nazis on the eve of World War II.

Sen. John McCain, an Arizona Republican and Navy veteran who was wounded and held prisoner in Vietnam, scolded his younger colleague for the remark, and not for the first time. Earlier this year, he referred to Cruz and several other tea party-backed Republicans as “wacko birds,” although he later apologized.

In this most recent instance, McCain reminded Cruz, who wasn’t in the Senate during the original health care debate, that every Republican voted against the law, which passed the Senate on a party-line vote in 2010.

“We fought as hard as we could in a fair and honest manner, and we lost,” said McCain, the GOP’s 2008 presidential nominee.

Defunding the law wasn’t worth shutting down the government, he said.

The Senate has seen worse behavior.

In 1902, John McLaurin, South Carolina’s junior senator, burst into the chamber and accused the state’s senior senator, Ben Tillman, of “a willful, deliberate and malicious lie.”

Tillman responded by punching McLaurin in the jaw. Both were Democrats.

The worst episode, what the Senate’s website calls “one of the most dramatic and deeply ominous moments in the Senate’s entire history,” occurred in 1856, when Democratic Congressman Preston Brooks of South Carolina walked into the Senate chamber and beat Republican Sen. Charles Sumner of Massachusetts, an opponent of slavery, senseless with a cane.

No blood has been spilled lately. Indeed, personal relationships matter in the Senate; it’s how work gets done, especially in committees.

“Anything that moves toward rupturing the relationship is something to be concerned about,” said Ross Baker, a political science professor and Senate expert at Rutgers University in New Brunswick, N.J.

Only months ago, Boxer and Vitter praised each other on the Senate floor after the Senate overwhelmingly approved the Water Resources Development Act, which they crafted together in the Environment and Public Works Committee. Boxer chairs the panel and Vitter is the ranking member.

But this week during a committee hearing on transportation funding, the two, who sit next to each other, barely spoke.

With the current transportation bill expiring in a year, and states potentially losing billions in federal funding if Congress doesn’t pass new legislation, “They do manage to patch things up,” Baker said. “Neither person wants a dysfunctional committee.”

Snowe said voters didn’t want a dysfunctional Congress, either. She recalled that through other rough periods, including a 21-day government shutdown in 1995-96, the impeachment trial of President Bill Clinton in 1998 and the divisive Supreme Court case that decided the 2000 presidential election, the Senate could still enact laws.

Whatever the differences, Snowe said, most people want to get things done.

“We don’t have to settle for this,” she said. “This is not irreparable.”

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